The invention relates to a viscoelastic, heat-activatable, single-sided adhesive tape and to its use for adhesive bonding of EPDM parts.
Heat-activatable single-sided self-adhesive tapes are known and are available commercially. In the automotive industry they are used preferably to bond EPDM rubber profile seals in the doorframe area. The products used for this purpose (e.g. 3M Automotive Structural Sealing Tape(copyright)) have a laminate structure with sealing compound, foam material and adhesive. On application, however, signs of detachment are evident after a certain time owing to compression primarily in the area of curvature.
The object of the invention is therefore to remedy this situation and hence to provide a product which combines good EPDM adhesion (following heat activation at e.g. 160xc2x0 C./1 minute) with optimum PSA adhesion, especially in the area of curvature to the painted sheet metal.
This object is achieved by an adhesive tape as characterized more closely in the claims.
The structure of this adhesive tape therefore features a laminate of two components: firstly a heat-activatable adhesive film strip and secondly a double-sided self-adhesive tape, termed a fixer.
Reactive resins which are particularly suitable in accordance with the invention are alkylphenol resins which are especially base-reactive, as are available commercially as polychloroprene-based adhesives, e.g. Alresen(copyright) PA 565 (Hoechst), whereas regarding the other components of the adhesive film strip reference is made in particular to DE 33 31 016.